Search results
Results from the WOW.Com Content Network
Hydroaluminations of terminal alkynes typically produce terminal alkenylalanes as a result. Selectivity in hydroaluminations of internal alkynes is typically low, unless an electronic bias exists in the substrate (such as a phenyl ring in conjugation with the alkyne).
It is a terminal alkyne. The compound is a common terminal alkyne substrate in diverse studies of catalysis. It is a colorless combustible gas. [1] 1-Butyne participates in reactions typical for terminal alkynes, such as alkyne metathesis, [2] hydrogenation, condensation with formaldehyde.
In organic chemistry, alkynylation is an addition reaction in which a terminal alkyne (−C≡CH) is added to a carbonyl group (C=O) to form an α-alkynyl alcohol (R 2 C(−OH)−C≡C−R). [1] [2] When the acetylide is formed from acetylene (HC≡CH), the reaction gives an α-ethynyl alcohol. This process is often referred to as ethynylation.
The Crabbé reaction (or Crabbé allene synthesis, Crabbé–Ma allene synthesis) is an organic reaction that converts a terminal alkyne and aldehyde (or, sometimes, a ketone) into an allene in the presence of a soft Lewis acid catalyst (or stoichiometric promoter) and secondary amine.
The acidity of the terminal alkynyl proton allows the alkynylzinc compound to be generated in situ from the appropriate alkyne with an alkylzinc reagent or zinc triflate, Zn(OTf) 2. [1] The first example of catalytic asymmetric addition of alkynylzinc compounds to aldehydes was reported by KensÅ Soai and co-workers in 1990.
The acidic hydrogen on terminal alkynes can be replaced by a variety of groups resulting in halo-, silyl-, and alkoxoalkynes. The carbanions generated by deprotonation of terminal alkynes are called acetylides. [5] Internal alkynes are also considerably more acidic than alkenes and alkanes, though not nearly as acidic as terminal alkynes.
It is a terminal alkyne, in fact the smallest that is liquid at room temperature. The compound is a common terminal alkyne substrate in diverse studies of catalysis. The compound is a common terminal alkyne substrate in diverse studies of catalysis.
1-Decyne is the organic compound with the formula C 8 H 17 C≡CH. It is a terminal alkyne.A colorless liquid, 1-decyne is used as a model substrate when evaluating methodology in organic synthesis.